AI model naming and versions · 2 min read

GPT-6 Astra vs. Claude 5.5: The Model Names Are Not One Release

A date-checked guide to separating OpenAI’s GPT-6 Astra from Anthropic’s Claude 5.5 family.

Release date: 2026-10-07. This update is based on the vendor’s announcement and was added to the Worksflow.ai guide on October 11, 2026.

The official announcements use two different naming systems: OpenAI calls its September flagship GPT-6 Astra, while Anthropic’s September and October releases are Claude Opus 5.5, Sonnet 5.5, and Haiku 5.5. “Astra 5.5” combines names from separate vendors and is not the product name used in either cited announcement.

What the update means

When documenting a model, record the vendor, exact model identifier, announcement date, API or app channel, and retrieval date. This prevents similarly numbered product families from being merged in comparisons or tool catalogs.

What to verify before you update a workflow

  • Confirm the exact model or product identifier in the vendor’s live documentation.
  • Check whether the announcement describes a general release, preview, or restricted rollout.
  • Test the same representative tasks, tool calls, and failure cases used in your current workflow.
  • Record the vendor’s source and the date your team checked it.

Official sources

Details and availability can change after publication. Recheck the source before acting on this guide.